Charging in communication systems

ABSTRACT

The present invention relates to charging of communications using chargeable resources of a first communication system and a second communication system wherein at least one of said communication systems provides wireless communication services. In accordance with the method, after a set-up procedure for communications initiated a first charging component is triggered, the first charging component being associated with the first communication system and determined based on a first charging model. If required, a second procedure for obtaining a second charging component is also triggered, the second charging component being associated with the second communication system and determined based on a second charging model. Information associated with the communications in the first and second communication systems is processed simultaneously to obtain the respective first and second charging components. The first and second charging components are combined to obtain a total charge. A prepaid balance is then decreased during the communications based on the total charge.

FIELD OF THE INVENTION

[0001] The present invention relates to charging in communicationsystems, and in particular to communication systems enabling prepaymentof communication services.

BACKGROUND OF THE INVENTION

[0002] A communication system may provide a subscriber with a fixed lineconnection or a wireless connection for communication, such as for voiceor data communication. An example of the fixed line systems is thepublic switched telephone network (PSTN). An example of a wirelesscommunication system is the public land mobile network (PLMN) andanother example is a satellite based mobile communication system. Thewireless communication occurs typically via a radio frequency connectionbetween the station of the subscriber and at least one network elementof the communications system. Communication within the network istypically, but not necessarily, handled by fixed line connectionsbetween the various network elements. Communication may also betransmitted in a system comprising one or more data networks. An exampleof this is the voice over IP (Internet Protocol) arrangement enablingvoice call over a packet switched data network. The communication systemmay also employ a combination of wireless, fixed line and/or datanetwork communication for a connection between two terminals. The term“connection” is intended to refer to all types of communication betweentwo signalling points, such as a user terminal. The communication viathe connection may be, for example, in the form of a voice call or amultimedia call or a data communication session.

[0003] A communication system typically operates in accordance with astandard or specification which sets out what the various elements ofthe network are permitted to do and how that should be achieved. Forexample, the standard or specification may define whether the user, ormore precisely, user equipment or terminal is provided with circuitswitched and/or packet switched service. The standard or specificationmay also define the various communication protocols and/or parameterswhich shall be used for the connection. In other words, the standardsand/or specifications define the “rules” on which the communication andvarious associated functions can be based on. The various functions thatare based on these rules may be arranged in predefined layers, e.g. toso called protocol stacks.

[0004] In addition to basic voice and data services, the users of thesubscriber terminals (such as fixed line telephones, data processingdevices or PLMN mobile stations) may be provided with additional oradvanced services. These can be defined as functions providing varioussophisticated services or value-added services to the subscribers, forinstance by means of software and/or hardware implementations providedin one or several nodes of the communication system. The additionalservices requested and subsequently invoked for a connection typicallyrequire control of at least one of the call management functions (e.g.routing, charging, duration, provision of connection or user relateddata and so on).

[0005] The additional services can be implemented by means of afunctionality that is often referred to as intelligent network (IN). Theterm “intelligent network” was introduced by the BELLCORE organisation(U.S.A.) in the mid eighties. The intelligent network (IN) concept wasdeveloped in order to increase the flexibility and competitiveness ofthe telecommunication network architecture. Even though the initial INarchitectures were developed to implement only certain specificservices, for example service number, the current IN solutions providethe communication network operators with a possibility to implement new,powerful services in their networks in a fast and cost-effective manner.

[0006] The basic principles and operation of the IN applications arewell known, and therefore they are not described herein in more detail.It is sufficient to note that in general the IN architecture comprises a(service) switching point (SSP) for triggering a call to the IN servicesand a (service) control point (SCP) for providing the service. The SSPand the SCP functions may be integrated in a service switching andcontrol point (SSCP). A more detailed description of the general INconcept can be found e.g. from the recommendations by the InternationalTelecommunications Union (ITU-T), such as IN Capability Set CS-1published in 1993. The IN concept can be implement in the fixed landline networks, such as the public switched telephone network (PSTN), orthe wireless radio communication networks, such as the public landmobile network (PLMN). Customised applications for mobile networkenhanced logic (CAMEL) application part (CAP) protocol may be used inthe SCP of a PLMN system for the provision of the service logic.

[0007] A service available for the subscribers is so called prepaidservice. In a prepaid service arrangement the user of a terminal, suchas a mobile station, may purchase beforehand a certain predefined amountof calling time or other service time. The prepaid amount will bereferred to as balance. The balance may be purchased in any appropriatemanner, e.g. by purchasing calling cards or vouchers, by means of a banktransfer, and so on. The balance will be stored in a prepayment accountimplemented by means of the intelligent network. The user may then makecalls against his/hers account until the balance in the prepaymentaccount runs out. It may also be possible for the user to reload morebalance in the account, or the user may simply purchase a new prepaidaccount after the balance in the previous account has run out. Althoughthe prepaid account holders can be identified, it is also possible thatthe prepaid accounts are anonymous, i.e. the operator does notnecessarily know the identity of the owner of the account.

[0008] In the prepayment service a call may be charged by deducting(decrementing) during the call the balance on the account based on acalculated charge parameter that will referred to herein as a callcharge. The call charge may be calculated based on a charging component.The call charge may be calculated by means of the intelligent networkbased on information that associates with the chargeable resource of thecommunication system. In some application the calculation isaccomplished by means of a controller of the network, such as the mobileswitching center or a specific billing centre. For example, in a GSMstandard (Global System for Mobile communications) the call chargecomponent may be calculated based on charging components that arereferred to as parameters or main charging zone (MCZ) parameters. Itshould be noted that other standards may employ differently namedparameters for the same purposes. The charging component for a call istypically obtained from a controller of the systems, such as from amobile switching center (MSC) of the GSM system, for the calculation ofthe call charge, i.e. the calculation of the amount that is to bededucted from the balance.

[0009] The operator of a network may want to offer free connection timeor other service time for the subscribers to the network. The operatormay wish to do so e.g. on selected days or selected times of a day. Ifthe operator wants to offer free airtime for those mobile subscribersthat use prepaid services, this may be accomplished at the mobilenetwork by waiving any airtime charges off. However, if the call is madeto a terminal connected to another network, e.g. to a terminal connectedto a PSTN, the operator of the originating network may become liable forclearing charges later on for the use of the resources of said othernetwork regardless the nature of the charging (post paid or prepaidcharging). Clearing of call charges incurred in the other networksusually takes few days to accomplish. The operators of the originatingnetwork may however, wish to charge also these charges from thesubscriber who originated the call even if the call was made by aprepaid subscriber.

[0010] To be able to establish at once the total call charge for callmade using the chargeable resources of at least two networks, theintelligent network (IN) of the originating network should know thecharging components from all networks involved. However, the controllerof the originating or first network (such as the MSC) does notnecessarily get this charging information from the destination or thesecond network in all current charging applications. This may causeproblems especially when the originating terminal pays for theconnection by means of a prepayment service, since the system should beable to deduct the charges during the connection from the balanceassociated with the originating terminal.

[0011] The above situation is clarified by means of the followingexample. Although the mobile switching center (MSC) of a PLMN system mayobtain the charging component that is associated with the charges in thePLMN system, the mobile switching center does not necessarily receiveall information required for the charging from the PSTN e.g. via ISUP(ISDN User part) signalling. If the operator of the PSTN does not wantto transfer charging messages via the ISUP signalling to other networks,such as to the PLMN, then the calculation of components need to begenerated in the PSTN where the charges incurred. That is, the requiredcharging definitions have to be precalculated in the home PSTN networkif the charging information is not transferred to other networks e.g. bymeans of the ISUP. The charges need also to be cleared later on betweenthe operators of the two networks. In the post paid chargingarrangements this is usually not a problem since the cleared charges canbe added to the bill of the PLMN subscriber later on in a billing centreof the PLMN operator. However, this is not possible with the subscribersto the prepaid services, as their charging should occur immediatelyduring the connection.

[0012] Although it may be possible to provide the controller of anetwork, such as the MSC of a PLMN, with information regarding the useof resources in all networks, the controller cannot calculate thesedifferent components separately. In conventional post-paymentarrangements this is not usually a problem since the charges for a callcan be sorted out later on. However, in the prepayment arrangements theservices have to be charged immediately. The services also have to becharged in their entirety during the call. The controller may not bemade aware of all of the charging components and/or the controller maynot be able to calculate all of the needed components and/or tocalculate the components separately. Therefore, although the originatingnetwork may be able to produce some kind of estimate of the charges forthe prepaid subscribers, the charging of the pre-paid subscribers maystill be inaccurate.

[0013] A problematic situation may also occur when more than oneindependently operating charging model is used for a call from a commontermination point. Different call charge control features used in thedifferent charging and tariff schemes may be in conflict with each otherand/or may not interact in a proper manner. The different chargingmodels and/or the charging components produced by the different modelsmay not even be used for a single connection.

[0014] For example, in some cellular communication systems the mobilestation originated call tariffs have two different components. Theexemplifying two components will be referred to as ‘an Airtime Charge’and ‘a PSTN charge’. These two components are first computedindependently and subsequently summed together e.g. in the post paymentbilling centre to obtain the total call charge. The Airtime rate maydepend on various parameters, such as the time of day, the subscribercategory, the rate plan to which the subscriber has signed on, thedestination of the call and so on. The PSTN component may also depend onvarious factors such as the time of day, the distance to the calleddestination, subscriber profile and so on. The Airtime and PSTNcomponents may increment in different time units. For example, theAirtime component may increment once per minute while the PSTN componentmay increase every 30 seconds. It is also possible that one of thecomponents is incremented in units that do not dependent on time (e.g.in pulses). The tariff structures of the two charging models may besubstantially different from each other.

[0015] A connection set-up procedure for establishing a connectionbetween two terminals may be based on use of a originating state model.One possible originating state model is the Originating Basic Call StateModel (OBCSM) of the Intelligent Network Application Part (INAP)protocol suite. The INAP OBCSM is a typical example of the first(originating) phase of call set-up procedures. However, the inventorshave found that the controller of the originating network cannotcalculate independently the two or more charging components at the sametime in a same originating state model. For example, the MSC is notenabled to handle simultaneously the two charging components in the sameprotocol (e.g. INAP or CAP) and to report them to the SCP independentlyfrom each other. Thus the service control point (SCP) may receiveinformation of one charging component only since only one protocol canbe used at the MSC. On the other hand, the inventors have also foundthat the SCP cannot proceed to calculate more than one of the chargingcomponents based on a single triggering at the service switching point(SSP).

SUMMARY OF THE INVENTION

[0016] Embodiments of the present invention aim to address one orseveral of the above problems.

[0017] According to one aspect of the present invention, there isprovided a method for charging in communication systems, the methodcomprising the steps of: initiating a set-up procedure forcommunications, the communications using chargeable resources of a firstcommunication system and a second communication system, at least one ofsaid communication systems providing wireless communication services;triggering in a charging function a first procedure for obtaining afirst charging component for the communications, the first chargingcomponent being associated with the first communication system anddetermined based on a first charging model; triggering in the chargingfunction a second procedure for obtaining a second charging componentfor the communications, the second charging component being associatedwith the second communication system and determined based on a secondcharging model; simultaneously processing in the charging functioninformation associated with the communications in the first and secondcommunication systems based on the first and second charging models toobtain the respective first and second charging components; combiningthe first and second charging components to obtain a total charge; anddecreasing a prepaid balance during the communications based on thetotal charge.

[0018] According to another aspect of the present invention there isprovided a arrangement for communication systems, comprising: a node ina first communication system for initiating a set-up procedure forcommunications via the first communication system and a secondcommunication system, at least one of said communication systemsproviding wireless communication services; trigger means for starting afirst procedure for obtaining a first charging component for thecommunications, the first charging component being associated with theuse of chargeable resources of the first communication system; triggermeans for starting a second procedure for obtaining a second chargingcomponent for the communications, the second charging component beingassociated with the use of chargeable resources of the secondcommunication system; and controller means responsive to triggeringsignals from the trigger means, the controller means being adapted forsimultaneous processing of charging information associated with thecommunications in the first and second communication systems to obtainthe respective first and second charging components, said first chargingcomponent being determined based on a first charging model and thesecond charging component being determined based on a second chargingmodel, for combining the first and second charging components to obtaina total charge, and for decreasing a prepaid balance based on the totalcharge during the communications.

[0019] The embodiments of the invention may enable prepayment servicesthat are capable of handling two or more different charging schemes. Itis possible to separate different charging components and/or tariffsand/or the processing thereof from each other. The embodiments mayenable a substantially real-time charging of the subscribers to prepaidservices during the communications even in occasions where anothernetwork does not provide charging information during the connection. Thesame solution may be used with overlay solution when a transit switchingcenter is used for triggering to the intelligent network services.

BRIEF DESCRIPTION OF DRAWINGS

[0020] For better understanding of the present invention, reference willnow be made by way of example to the accompanying drawings in which:

[0021]FIG. 1 is a schematic presentation of a communication system;

[0022]FIG. 2 is a schematic presentation illustrating call state modelsand triggering of IN calls;

[0023] FIGS. 3 to 5 illustrate one embodiment of the present invention;and

[0024]FIG. 6 is a flowchart illustrating the operation of one embodimentof the present invention.

DESCRIPTION OF PREFERRED EMBODIMENTS OF THE INVENTION

[0025] Reference is made to FIG. 1 which shows a communication systemconsisting of two different networks 1, 2 in which the embodiments ofthe present invention may be used. More particularly, FIG. 1 shows aPSTN network 1 and a PLMN network 2 and gateway means 3 between the twonetworks. A terminal 5 subscribing to the PSTN 1 is shown to have afixed line connection with the PSTN system 1. A mobile station 6 isenabled to communicate over a wireless connection with a base station 7of the PLMN system 2.

[0026] It should be appreciated that although the following embodimentsdescribe elements and functions of a GSM PLMN system and a conventionalPSTN this invention is also applicable to any other standard andcommunication system as well where applicable. For example, withoutlimiting to these, the connection may originate from and/or terminate ina third generation communication system, such as the UMTS (UniversalMobile Telecommunication system) or i-Phone or IMT 2000 (InternationalMobile Telecommunication System 2000) and so on.

[0027] The PLMN system of FIG. 1 is shown to comprise a controller 9.More particularly, the shown controller comprises a mobile switchingcenter (MSC) adapted to operate in accordance with the GSM standard. Itshould be appreciated that the PSTN and PLMN networks may comprisevarious other elements, such as switches, various controllers andgateways and internal connections for enabling communication between twoor several terminals than those elements that are shown in FIG. 1.However, for clarity reasons and since the other elements and/orconnections are not important in understanding the invention, they areshown and described in more detail.

[0028]FIG. 1 shows further a service switching point (SSP) 11 as anentity integrated with the mobile switching center 9. The switchingpoint is adapted to trigger any signalling that requires processing by aservice control point (SCP) 11 of the IN arrangement to be directed tothe SCP. The SSP enables enquiries for instructions or any othernecessary signalling between the MSC 9 and the SCP (the serviceprovider) 11. In other words, the MSC/SSP node 9, 10 is for providingtriggering functions for the embodiments.

[0029] The service control point (SCP) 11 is in turn provided for thecontrol of the prepayment services provided for the A-subscriber 6. Inthis example the A-subscriber refers to the calling subscriber i.e. theoriginating party of a call. The control point 11 contains necessarydata and logic for the given IN service. In general, the service controlpoint 11 may receive a request from the service switching point, executethe requested services and return the necessary information or otherdata to the switching point. The control point 11 is enabled to handlevarious functions, such as charging and management of the used services.An appropriate general functional definition element (FDE) may be usedin the implementation of the SCP 11. It should be appreciated that theSCP 11 may be designed according to any special needs by the operators.

[0030] The service control point 11 implements an account 12 for storinga prepaid balance for the mobile subscriber 6. The balance on theaccount is decrement based on computed overall charge for the usedservices, as will be explained in more detail below.

[0031]FIG. 2 shows how the signalling within the IN system may bearranged during call set-up procedures relative to the different callstate models of the Intelligent Network Application Part (INAP) protocolsuite. The interface between the mobile switching centre and the servicecontrol point may be based on the intelligent network applicationprotocol (INAP) and/or the customised applications for mobile networkenhanced logic (CAMEL) application part (CAP) protocol. So called CAMELservice environment (CES) may be used to provide the executionenvironment within a CAMEL SCP executing a service logic, the CAMELprotocol being an internal protocol for the SCP.

[0032] Before explaining the preferred embodiment in more detail, abrief description of possible call state models will be given withreference to FIG. 2, as this is believed to help in understanding theembodiment. During the call set-up the service control point (SCP) 11controlling the calling subscriber may have signalling connection forreceiving and/or sending information during an Originating Basic CallState Model (OBCSM) of the Intelligent Network Application Part (INAP)protocol suite. The OBCSM is typically the first (originating) phase ofthe call set-up after an IAM (Initial Address Message) arrives the MSCcontroller 9. FIG. 2 illustrates also a Terminating Basic Call StateModel (TBCSM) of the INAP protocol suite, which is a later phase of thecall processing model.

[0033] The embodiments described in the following may provide a feasiblesolution to a situation where call charging needs to be based on two (ormore) different charging components, for example on fixed line systemcharges and wireless system charges. In a preferred embodiment separatecharging function and tariffs function are provided for both components.The processes used for obtaining the different charging components arepreferably run independently from each other. Information about thetotal charge is obtained by combining the charging components at theservice control point 11. Before the combining procedures, the servicecontrol point may convert one of the components or even or allcomponents into a compatible format.

[0034] Reference is now made to FIGS. 3 to 5 illustrating the preferredembodiment employing two separate prepayment service functions in a SCPnode 11 for charging a connection initiated by a mobile station A andreceived by another station B subscribing to another network.

[0035] Two different protocols are used for the overall call charging.As shown by FIG. 3, in the preferred embodiment a CAMEL Phase 2 i.e. CAPPhase 2 protocol is used for the airtime charging in the OBCSM callstate for the mobile station A. FIG. 4 in turn shows use of Core INAPfor the PSTN charging between the SCP 11 and the MSC 9. Core INAP is aprotocol defined by the European telecommunications Standards Institute(ETSI). FIG. 5 shows the situation during the ongoing call between theterminals 5 and 6, i.e. when the two different charging servicesinitiated in FIGS. 3 and 4 are active at the same time.

[0036] As shown in FIG. 4, a feature interaction manager 13 may beprovided in the system to handle the processing of the differentprotocols and the triggering required in the Originating Basic CallState Model (OBCSM) of the Intelligent Network Application Part (INAP)protocol suite. The feature interaction manager 13 may be implemented inassociation with the mobile switching center 9. In a preferredembodiment the feature interaction manager is implemented in the callprocessing software of the mobile switching center 9.

[0037] The triggering in the SSP 10 may be adapted to occursubstantially at the same time for the two protocols during the callset-up procedure. As a result, the two protocols can be processedsimultaneously at the SCP 11. The intelligent network (IN) arrangementcan be adapted to define the two charging components independently fromeach other when the CAMEL and Core INAP Protocols are usedsimultaneously. In the case of a speech call between the two terminals,the call is triggered twice before the establishment of the real speechconnection. A preferred order for the triggering is such that the CAMELprotocol i.e. the airtime charging is triggered first and the INAPprotocol i.e. the fixed line charging is triggered next. The speechconnection is established only after these two triggering and necessarytariff definitions.

[0038] As already mentioned, airtime charge can be defined based on useof the CAMEL phase 2 protocol. The SCP may use an appropriate internalcharging scheme for the calculation of the airtime charging componentand an appropriate charging software.

[0039] The PSTN component may be defined by using Core INAP protocol andMSC charging scheme that is controlled by the SCP 11. PSTN tariffstructures may need to be defined by the operator and stored to aservice management point (SMP) e.g. via a service management interface(SMI) client. The tariff plan may be changed if necessary. Thesefeatures as such are known by the skilled person, and will be notexplained in more detail.

[0040] two triggerings are needed when a mobile subscriber (A-number)calls to a PSTN subscriber (B-number) in order to initiate simultaneousseparate computation of the two separate charging components before thecall connection is established. The first triggering preferably occursin the CAMEL DP2 as the call is initiated. In FIG. 3 the firsttriggering is shown to initiate ‘paid 1 service’ procedure at the SCP 11for the airtime charging component. This procedure may comprise thefollowing steps: checking of the time and/or day, checking thesubscriber category or class, checking the account information, startinginternal charging and so on.

[0041] The second triggering occurs in the Core INAP TDP3 based onB-number analyses. In FIG. 4 the second triggering is shown to initiate‘prepaid service 2’ procedures at the SCP 11 for the PSTN component. Thesecond procedure may comprise the following steps: checking of the timeand/or day, checking the B-number and dependencies it may have, checkingcall distance information, obtaining the PSTN tariff, and so on.

[0042] The B-number analysis comprises determination whether theB-number is a PSTN number or another mobile station number subscribingto the same network as station 6. If the B-number is detected to beanother number in the same network or a number of any other such networkwhich does not require calculation of a second charging component, nofurther triggering will occur and the ‘prepaid 2 service’ will not beactivated. Instead, the charging may be handled in a usual way.

[0043] After the checking procedures and the activation of the ‘prepaid2 service’ the SCP 11 will provide the MSC with necessary information,such as with ‘send charging information’ (SCI: this is an INAPoperation) parameters regarding e.g. the charging zone and e-parameteras well as RRB parameters (‘Request Report BCSM’: an INAP operation) maybe provided to the MSC 9 and the call may be connected. During the callthe MSC may provide the SCP with an INAP message ‘Apply Charging Report’regarding the PSTN charging in accordance with the definitions by theSCP. The balance in the A-subscriber account is then decrement based onthe report. This report includes information such as time value or pulseamount that may be used in the determination of the cost of the PSTNpart of the call. During the charging procedure the determinedcomponents for the ‘prepaid 1 service’ and ‘prepaid 2 service’ arecombined by the SCP and the overall call charge is decrement from thecommon account 12.

[0044] Thus, by means of the two triggerings the two required chargingcomponents can be determined independently from each other. Instead ofhaving separate accounts for the two charging components, only oneprepaid account 12 is provided in the SCP 11. The balance on the account12 is consumed based on the combined charge.

[0045] The final calculation i.e. the possible converting and combiningof the separate charging components occurs in the above describedembodiment in the service control point 11. The charging components maybe both computed at the service control point. Alternatively, at leastone charging component or basic information required for thedetermination of a charging component may be computed at the networkcontroller 9. The overall control of the computation of the individualcharging components will be handled by the service control point 9. Ifcalculated by the controller 9, the reporting of information associatedwith the different charging components to the service control point 11may occur in separate messages. The service control point may thencombine the information transported in the separate messages to obtainthe total charge for the connection.

[0046] The MSC 9 may generate CDR's (call detailed record comprisingcharging ticket in the MSC or in the SCP) if these are needed e.g. forpost processing purposes or clearing purposes between the operators.

[0047] The operators may be able to use the existing functionality whendefining any post paid tariffs in the billing system. To be able toaccomplish this a connection to the IN may be needed.

[0048] According to one possibility same charging service may be usedwith roaming subscribers than with the actual subscribes of a network.However, if a subscriber roaming in a PLMN calls e.g. to a PSTNsubscriber, this may need some cooperation between the operators ofthese two networks. Some routing rules may also be required to bedefined in the home network of the subscriber. That may be required whenthe call is triggered for the first time in the visited PLMN and routedto the home PLMN, since the call has to be triggered again for examplein the International gateway Exchange (e.g. in a TDP3 based on B-numberanalyses) in order to enable definition of the PSTN component.Naturally, this is needed only if a PSTN component is needed and thecall is a PSTN terminated call.

[0049] The above described combining of the two (or several) componentstogether may assist in solving the problem relating to different typesof charging schemes. Calculation of the two individual chargingcomponents e.g. in the MSC 9 may be initiated for the two individualcharging components in the same OBCSM. The SCP 11 may therefore startusing the two (or more) charging models simultaneously. The embodimentsavoid transmission of charging messages in the ISUP, e.g. for enablingcharging of the prepaid customers during the call. Instead, theoriginating network operator himself may prepare a substantiallyaccurate charging component(s) for the use of the other network(s) andcharge the subscriber accordingly in real time. The embodiments may useexisting software and/or hardware functions. The embodiments may bebased on the functionality of existing a mobile switching center/homelocation register (MSC/HLR) and IN arrangements.

[0050] It should be appreciated that whilst embodiments of the presentinvention have been described in relation to mobile stations,embodiments of the present invention are applicable to any othersuitable type of user equipment.

[0051] It should be appreciated that an IN based prepayment service maybe implemented within the same node with the other IN services that maybe provided for the A-subscriber 6. The service switching point andcontrol point may also be implemented within one node (e.g. within atelephone exchange or a radio network controller or a switching centre).In such case the integrated node then functions for both detection ofconnections requiring use of IN services and execution of the servicelogic.

[0052] The embodiment of the invention has discussed the triggering froma SSP and processing in a SCP. Embodiments of the present invention canbe applied to other network elements where applicable.

[0053] It is also noted herein that while the above describesexemplifying embodiments of the invention, there are several variationsand modifications which may be made to the disclosed solution withoutdeparting from the scope of the present invention as defined in theappended claims.

1. A method for charging in communication systems, the method comprisingthe steps of: initiating a set-up procedure for communications, thecommunications using chargeable resources of a first communicationsystem and a second communication system, at least one of saidcommunication systems providing wireless communication services;triggering in a charging function a first procedure for obtaining afirst charging component for the communications, the first chargingcomponent being associated with the first communication system anddetermined based on a first charging model; triggering in the chargingfunction a second procedure for obtaining a second charging componentfor the communications, the second charging component being associatedwith the second communication system and determined based on a secondcharging model; simultaneously processing in the charging functioninformation associated with the communications in the first and secondcommunication systems based on the first and second charging models toobtain the respective first and second charging components; combiningthe first and second charging components to obtain a total charge; anddecreasing a prepaid balance during the communications based on thetotal charge.
 2. A method as claimed in claim 1, wherein the firstcommunication system comprises a mobile communications network providingwireless communication services for mobile stations.
 3. A method asclaimed in any preceding claim, wherein the second communication systemcomprises a fixed line communication network.
 4. A method as claimed inclaim 3, wherein the fixed line communication network comprises a publicswitched telephone network.
 5. A method as claimed in any precedingclaim, wherein the first and the second charging procedures aretriggered in a controller of the first communication system.
 6. A methodas claimed in claim 5, wherein the controller comprises a switchingcenter of the first communication system.
 7. A method as claimed in anypreceding claim, wherein determination of each of the chargingcomponents is based on the charging and tariffs scheme used by therespective communication system.
 8. A method as claimed in any of thepreceding claims, wherein said simultaneous processing is accomplishedin a controller of an additional service.
 9. A method as claimed inclaim 8, wherein the controller comprises a service control point of anintelligent network arrangement.
 10. A method as claimed in any ofclaims 1 to 7, wherein at least a part of the simultaneous processing isaccomplished in a controller of the first communication system.
 11. Amethod as claimed in any preceding claim, wherein the triggering of thefirst and second procedures is accomplished at a service switching pointof an intelligent network arrangement.
 12. A method as claimed in any ofclaims 8 to 11, wherein the balance is decreased during thecommunications from a prepayment account implemented by the service. 13.A method as claimed in any preceding claim, comprising triggering aprocedure for determining at least one further charging component andsimultaneous processing of said at least one further charging componentin the charging function.
 14. A method as claimed in any precedingclaim, comprising a step of converting at least one of the obtainedcharging components to a form that can be combined with at least oneother of the charging components.
 15. A method as claimed in anypreceding claim, wherein one of the charging components is obtainedbased on intelligent network application protocol (INAP) and another oneof the charging components is obtained based on customised applicationsfor mobile network enhanced logic application part protocol (CAP).
 16. Amethod as claimed in any preceding claim, comprising a step of analysingif determination of the second charging component is required priorinitiating the processing for obtaining said second charging component.17. A method as claimed in any preceding claim, wherein the triggeringof the first and second procedures occurs during an originating phase ofthe call set-up procedures, preferably during originating phase basiccall state model (OBCSM).
 18. An arrangement for communication systems,comprising: a node in a first communication system for initiating aset-up procedure for communications via the first communication systemand a second communication system, at least one of said communicationsystems providing wireless communications; trigger means for starting afirst procedure for obtaining a first charging component for thecommunications, the first charging component being associated with theuse of chargeable resources of the first communication system; triggermeans for starting a second procedure for obtaining a second chargingcomponent for the communications, the second charging component beingassociated with the use of chargeable resources of the secondcommunication system; and controller means responsive to triggeringsignals from the trigger means, the controller means being adapted forsimultaneous processing of charging information associated with thecommunications in the first and second communication systems to obtainthe respective first and second charging components, said first chargingcomponent being determined based on a first charging model and thesecond charging component being determined based on a second chargingmodel, for combining the first and second charging components to obtaina total charge, and for decreasing a prepaid balance based on the totalcharge during the communications.
 19. An arrangement as claimed in claim18, wherein the trigger means are located in said node.
 20. Anarrangement as claimed in claim 18 or 19, wherein said node comprise aswitching centre of a mobile communications network.
 21. An arrangementas claimed in any of claims 18 to 20, wherein the trigger means comprisea service switching point of an intelligent network arrangement adaptedto trigger the said two procedures during originating state of theset-up procedure.
 22. An arrangement as claimed in any of claims 18 to21, comprising a feature interaction manager for use in the control ofthe different charging models and the triggering.
 23. An arrangement asclaimed in claim 22, wherein the feature interaction manager isimplemented in association with said node.
 24. An arrangement as claimedin claim 22 or 23, wherein the feature interaction manager isimplemented in a call processing software of said node.
 25. Anarrangement as claimed in any of claims 18 to 24, wherein the controllermeans comprises a service control point of an intelligent network. 26.An arrangement as claimed in claim 25, wherein the controller meanscomprises further a mobile switching centre.